Integral main drive member for sewing machines



F. WIEHL 3,103,190

INTEGRAL MAIN DRIVE MEMBER FOR sEwINc MACHINES Sept. 10, 1963 2 Sheets-Sheet 1 Filed March 1'7, 1961 INVENTOR. Frederick R. Wiehl BY My, 6W ATTORNEY WITNESS W /QMW Sept. 10, 1963 F. R. WIEHL 3,103,190

INTEGRAL MAIN DRIVE MEMBER FOR SEWING MACHINES Filed March 1'7, 1961 2 Sheets-Sheet 2 INVENTOR. Frederick R. Wieh/ WITNESS wa -wan Fig. 2 W

United States Patent 3,103,190 INTEGRAL MAIN DRIVE MEMBER FOR SEWING MACHINES Frederick R. Wiehl, Westfield, N .J assign'or to The Singer Company, a corporation of New Jersey Filed Mar. 17, 1961, Ser. No. 96,564 Claims. (Cl. 112220) This invention relates to sewing machines, and more particularly, .to a novel and improved main driving member for a sewing machine.

In sewing machine construction, it is conventional to provide an arrangement of interconnected driving elements usually assembled on a shaft journaled in the bracket arm of the sewing machine casing. The main drive shaft may be driven by a motor or a treadle device and in the conventional arrangement is adapted to have secured thereto a plurality of separately manufactured driving elements such as a feed cam or eccentric, a loop taker driving element, and driving elements for the needle bar and needle thread take-up. If counterweights are provided in the known construction, it is conventional that they be provided as elements manufactured separately and then assembled on and secured to the drive shaft. Where a crank has been used tovdrive' the loop taker, it has been known in the art to'providea steel main drive shaft on which the crank is forged. It is also conventional to provide shaft bushings, where required, as separately machined elements which are assembled on the main drive shaft along with the various driving elements prior to installation of the main drive shaft into .the machine casing.

It is an object of this invention to provide a sewing machine main drive member in which the driving "elements, counterweights, and bushings are formed integrally therewith. Among the many advantages of .this novel and improved main drive member are the drastic reduc: tion in the number and complexity of machining operations necessary to provide a finished main drive unit for a sewing machine, the permanence of the relationships of axial and angular position of the various driving and counterbalancing elements associated with a main drive member in accordance with this invention, and the elimination of the many subassembly operations which had been necessary with the conventional construction.

It is an object of this invention to provide a sewing machine main drive member with a novel arrangementof driving elements, counterbalances, and bushings which may be fabricated as an integral unit with a reduction in the mass as compared with conventional constructions,

thus reducing the cost of materials used in sewing machine construction.

A further object of .this invention is to provide a novel form for a sewing machine main drive member which may be fabricated as an integral casting of grey cast iron, various aluminum alloys, or the like with the consequent advantages that the surfaces requiring high tolerances may be machined easily and economically, that heat treatment is obviated and with it stress concentrations, dimensional changes, and surface deterioration which may result from heat treatment, and that the superior vibration damping qualities of a cast metal may be obtained.

With the above and other objects and advantages in view as will hereinafter appear, this invention comprises the devices, combinations and arrangements of parts hereinafter described and illustrated in the accompanying drawings of a preferred embodiment in which:

FIG. 1 represents a longitudinal vertical cross sectional view of a sewing machine having a main drive member in accordance with this invention,

FIG. 2 is a transverse vertical cross sectional view through the standard and bed of the sewing machine 3,lh3,l% Patented Sept. 10, 1963 "ice of FIG. 1, taken substantially along the line 2-2 of FIG. 1,

FIG. 3 represents a side elevational view of the main drive member of FIG. 1,

FIG. 4 represents a left end elevational view of the drive member of FIG. 3, and

FIG. 5 is a cross sectional view of the main drive member, taken substantially along line 5-5 of FIG. 3.

, theretoand is pivotally connected as at 18 to a drive link 19. Also arranged in the bracket arm is a needle thread take-up lever 20 sustained by means of an anchor "link 21 fulcrumed in the bracket arm.

Cooperating with the needle in the concatenation of threads to form lock stitches is a loop taker 30 carried on a loop taker shaft 31 journaled beneath the bed.

The loop taker illustrated in the drawings is a conventional oscillatoryshuttle, however, any known type of loop taker may be used with this invention. As illustrated in the drawings, a rock arm 32 on the loop taker drive shaft carries a slide block 3-3 embraced by a forked arm 34 formed on a rock frame 35 journaled on the bed. An arm 36 on the rock frame 35 is pivotally connected to a looper driving pitman 37 disposed in the hollow standard.

The sewing machine fllustrated in FIGS. 1 and 2 includes a work feeding mechanism of the type commonly referred to in the art as a four-motion drop-feed and including a feed dog 40 working upwardly through slots in a throat plate 41 fitted on the bed and carried by a feed bar 42. Rising and falling motion is imparted to the feed bar and feed dog by means of a feed lift rock shaft 43 journaled in the bed and deriving oscillatory motion from a cam 44 on the looper driving rock frame 35 by way of a bifurcated cam follower 45 fast on the feed lift rock shaft. Feed advance and return motions are imparted to the feed bar and feed dog by a feed advance rock shaft 46 journaled in the bed and carrying a rock arm 47 pivotally connected to a feed drive pitman d8 in the standard which is formed with bifurcated feed cam embracing jaws 49. The feed drive pitman 48 has pivoted thereto a slide block 50 constrained in a slotted guide member 51 pivoted inside the machine standard. By means of a feed adjusting arm 52 extending from the guide member, the angular position of the guide member 51 and hence the extent and direction of work feeding motion imparted to the feed dog may be regulated under the influence of the machine operator.

For driving the needle bar drive link 18, the takeup lever 19, the looper driving pitman 37 and the feed advance pitman 48, there serves in this invention an integral main driving member indicated generally at 60 in the drawings. The main driving member 6% is illustrated as assembled in the sewing machine in FIG. 1 and is illustrated in FIG. 3 detached from the mechanism which it operates.

As illustrated in'FIG. 3, the main drive member 60 is an integral part formed as a single casting which is prefierablyof grey cast iron but might also be made of other 1 castable material such as an aluminum alloy or the like.

The main drive member is formed at one end with a cylindrical free extremity 61 concentric to an axis xx of turning movement of the main drive member, and a hearformed with an offset crank 63 for actuating the looper driving pitman 3-7. A feed cam 64 is formed on the main drive member adjacent the crank 63, which feed cam may be of the three cornered variety as illustrated in FIG. 5 or might be in the form of a plain eccentric if so desired.

Adjacent to the feed cam, the main drive member is formed with a spacer portion 65 concentric with the axis x-x of the main drive member which serves as a support for the member in the machining operations necessary thereon and also as a spacer between the feed cam portion and a counterbalance portion 66 which is substantially circular in cross section but offset eccentrically from the axis xx. The counterbalance portion 66 extends to an enlarged bearing journal 67 formed concentric to the axis xx formed near the extremity of the main drive member. The bearing journal 67 may be of a diameter greater than the diameter of a circle encompassing the axial projection of the main drive member from the journal 67 to the free extremity 61 so that the main drive member may be inserted axially through .a bearing dimensioned to accommodate the bearing journal 67. Because of the concentric spacer portion 65, .however, the bearing journal may be made considerably smaller in diameter and still admit insertion of the main drive member through a bearing sized to'accommodate the bearing journal 67. It is sufiicient to accommodate insertion of the main drive member if the bearing journal 67 be of a diameter at least as large as the diameter of the smallest circle which will encompass the projection parallel to the axis xx of any section of the main driving member at least equal in length to that of the bearing journal 67, said length considered from the counterbalance portion 66 to an enlarged counterbalance portion 70. Since the counterbalance portion 66 is offset from the axis xx on the side opposite that of the feed cam 64 and the looper driving crank .63, the spacer portion 65 in separating these oppositely offset portions along the axis x-x provides for insertion of the main drive member through a smaller bearing aperture than would be necessary .if these portions closely adjoined.

The free extremity of the main drive member at the bearing journal 67 is formed with a surface 68 perpendicular to the axis x--x in which is formed a needle bar actuating crack pin accommodating bore 69 parallel to the axis xx. The free extremity of the bearing journal 67 may be formed with a radially enlarged counterbalance portion 70 to offset and counterbalance a crank pin 71 which is carried in the bore 69. The free extremity of the bearing journal :67 may also be formed with .a blind bore 72 for the purpose of reducing the total weight of the main drive member. The bore 72 may be formed concentric with the axis xx solely for weight reduction, or the bore may be also disposed eccentrically thereof to have a counterbalancing effect on the main drive member.

Referring to FIG. 1, the main drive member 60 is journaled for turning movement on the sewing machine bracket arm 13, the bracket arm being provided with a bearing 86 near the standard 12 to accommodate the bearing journal 62 and also being provided with a bearing 81 formed near the free extremity of the bracket arm to accommodate the bearing journal 67. The bearings 80 and 81 need not be of any greater length than the bearing journals 62, 67 respectively with which they cooperate. The bearings 80 and 81 may be formed directly in the bracket arm particularly if the material from which the bracket arm is made is a grey cast iron, however, bushings might also be used if the bracket arm material were to be unsuitable for use as :a, bearing.

The integral main driving member 69 may be inserted in place in the braket arm through the open free extremity of the bracket arm before the end cover plate 14 and the needle bar have been assembled on the machine. The enlarged counterbalance portion 76 extending radially from the bearing journal 67 provides a shoulder 32 cooperating with the bearing 81 to locate the main drive member axially in the bracket arm. A balance wheel pulley 83 secured to the free extremity 61 of the main drive member provides not only a means for turning the main drive member from a motor or treadle or the like but also serves to secure the main drive member in place in the bracket arm.

Once the main drive member is inserted into the bracket arm, the various connections thereto are easily made, the loop taker driving pitman 37 is operatively connected to the crank 63 by a split bushing 84 secured on the pitman by the screws 35. The bifurcated jaws 49 of the feed drive pitman need merely be shifted into position embracing the feed cam 64. These pitman connections are accessible not only :upwardly through the hollow standard but also through a conventional access opening 86 in the bracket arm. The guide member 51 provides lateral support in one direction for the pitman 48 while a flange 87 at one side of the feed cam may be provided as an integral part of the main drive member for preventing lateral motion of the feed driving pitman in the opposite direction. The take-up lever 20 and the needle bar drive link 19 are assembled so as to embrace the crank pin 71 which is set into the bore 69 in the main driving member in an assembly operation accessible through the open free extremity of the bracket arm.

Having thus set forth the nature of this invention, what I claim herein is:

' 1. In a sewing machine having a hollow frame formed integrally with spaced coaxial bushings, an endwise reciprocable needle bar carried in said frame, a driving link associated with said needle bar, a loop taker journaled in said frame, an operating member drivingly connected to said loop taker, a work feeding mechanism carried in said frame, and a feed driving member operatively connected with said work feeding mechanism for imparting rfeed ad- 'vance motion thereto, a main driving member comprising one integral part formed with spaced coaxial cylindrical bearing portions each adapted to be journaled directly in one of said frame bushings, rotary actuating means formed on said main driving member between said bearings for imparting motion to said looper operating member, rotary actuating means formed on said main driving member between said bearings for imparting motion to said feed driving member, one of said bearing portions being at least as large in diameter as the diameter of the smallest circle which will encompass the projection axially of said bearing portions of any section of said main driving member at least equal in length to [that of said one cylindrical bearing portion and disposed onthat side of said one bearing portion on which said other bearing portion is formed, and said main driving member adjacent to said one cylindrical bearing portion and at the opposite side thereof :from said other bearing portion being formed with crank pin accommodating bore substantially parallel to and spaced from the axis of said bearing portions.

*2. In a sewing machine having a frame formed integrally with spaced coaxial bushings, an endwise reciprocable needle bar and a circularly movable loop taker carried in said frame, an integral main driving member comprising a continuous elongate body cformed with spaced coaxial cylindrical bearing portions, a loop [taker driving crank formed between said bearing portions, one of said bearing portions being 'langer in diameter than the smallest circle which will encompass the projection axially of said bearing portions of said loop taker dniving crank, and said main driving member adjacent to said one cylindrical bearing portion and at the side thereon opposite from said loop taker driving crank being formed with a needle bar actuating crank pin accommodating bore disposed substantially parallel to and spaced (from the axis of said bearing portions.

3. In a sewing machine having a hollow frame \formed with spaced coaxial bushings, an endwise reciprocable needle bar and a circularly movable loop taker carried in said zframe, an integral main driving member comprising a continuous elongate body termed with spaced coaxial cylindrical bearing portions, a loop taker driving crank formed between said bearing portions, one of said bearing portions being larger in diameter than the smallest circle which will encompass the projection axially of said bearing portions of said loop taker driving crank, and said main driving member adjacent to said one cylindrical bearing portion and at :the side thereof opposite from said loop taker driving crank being dormed with a portion of diameter larger than said one bearing portion defining a shoulder disposed in a' plane perpendicular to the axis of said bearing portions in abutting relation to one of said frame bushings for location of said main driving member axially in said sewing machine frame, and said portion of said main drive member of diameter larger than said one bearing portion being iormed with a needle bar actuating crank pin accommodating bore disposed substantially parallel to and spaced-[from the axis of said bearing portions.

4. In a sewing machine having a [frame including a hollow bracket arm formed with spaced coaxial bushings of ditfierent diameter, an endWise reciprocable needle carried in said frame, a loop taker journaled in said frame and cooperating with said needle in the formation of stitches, and a work feeding mechanism in said :frame tor advancing work lfabrics relatively to said needle and loop taker, an integral main driving member comprising a continuous elongate body dormed with spaced coaxial cylindrical bearing portions of dilferent diameters each adapted to be journaled directly in one of said frame bushings, cam means lfOI' actuating said work feeding mechanism formed between said bearing portions, said bearing portion of largest diameter being larger in diameter than the smallest circle which will encompass the projection axially of said bearing portions of said cam means, and said main driving member adjacent to said bearing portion of largest diameter and at the side thereof opposite from said cam means being formed with a needle actuating crank pin accommodating bore disposed 6 i substantially parallel to and spaced tfrom the axis of said bearing portions.

5. In a sewing machine having a frame including a hollow bracket arm formed with spaced coaxial bushings of difierent diameters, an endwise reciprocable needle bar carried in said frame, a circularly moving loop taker journaled in said frame, and a Work feeding mechanism in said frame, an integral main driving member comprising a continuous body formed with spaced coaxial cylindrical bearing portions of different diameters each adapted to be journaled directly in one of said frame bushings, a loop taker driving crank formed between said bearing portion, a feed actuating cam stormed between said heating portions, said main driving member between said bearing portions being formed with a cylindrical portion having an axis parallel to and spaced item that of said bearing portions to counterbalance said loop taker driving crank and said feed actuating cam, said bearing portion of largest diameter being at least as large in diameter as the diameter of the smallest circle which will encompass the projection axially of said bearing portions of any section of said main driving member at least equal in length to that of said frame bushing of largest diameter and disposed on that side of said bearing portion on which said other bearing portion is formed, and said main driving member adjacent to said bearing portion of largest diameter and at the opposite side thereof from said other bearing pontion being formed with a needle bar actuating crank pin accommodating bore substantially parallel to and spaced item the axis of said bearing portions.

References Cited in the file of this patent UNITED STATES PATENTS Sweden Feb. 26, 1935 

1. IN A SEWING MACHINE HAVING A HOLLOW FRAME FORMED INTEGRALLY WITH SPACED COAXIAL BUSHINGS, AN ENDWISE RECIPROCABLE NEEDLE BAR CARRIED IN SAID FRAME, A DRIVING LINK ASSOCIATED WITH SAID NEEDLE BAR, A LOOP TAKER JOURNALED IN SAID FRAME, AN OPERATING MEMBER DRIVINGLY CONNECTED TO SAID LOOP TAKER, A WORK FEEDING MECHANISM CARRIED IN SAID FRAME, AND A FEED DRIVING MEMBER OPERATIVELY CONNECTED WITH SAID WORK FEEDING MECHANISM FOR IMPARTING FEED ADVANCE MOTION THERETO, A MAIN DRIVING MEMBER COMPRISING ONE INTEGRAL PART FORMED WITH SPACED COAXIAL CYLINDRICAL BEARING PORTIONS EACH ADAPTED TO BE JOURNALED DIRECTLY IN ONE OF SAID FRAME BUSHINGS, ROTARY ACTUATING MEANS FORMED ON SAID MAIN DRIVING MEMBER BETWEEN SAID BEARINGS FOR IMPARTING MOTION TO SAID LOOPER OPERATING MEMBER, ROTARY ACTUATING MEANS FORMED ON SAID MAIN DRIVING MEMBER BETWEEN SAID BEARINGS FOR IMPARTING MOTION TO SAID FEED DRIVING MEMBER, ONE OF SAID BEARING PORTIONS BEING AT LEAST AS LARGE IN DIAMETER AS THE DIAMETER OF THE SMALLEST CIRCLE WHICH WILL ENCOMPASS THE PROJECTION AXIAL- 